Magnetic tape cartridge

ABSTRACT

A magnetic tape cartridge made up of a cartridge case composed of an upper and lower cases welded together on the mating surfaces by ultrasonic welding with a plurality of energy directors, and a single reel of magnetic tape rotatalby retained in the case, in which the weld deposits formed by the energy directors may be prevented from sticking out of the mating surfaces. A plurality of energy directors provided on one of the mating surfaces have an elongated shape, and are disposed with the longitudinal direction substantially perpendicular to the direction along the side wall of the upper and lower cases.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a magnetic tape cartridge havinga single reel of magnetic tape rotatably retained therein.

[0003] 1. Description of the Related Art

[0004] Conventionally, the magnetic tape cartridge having a single reelof magnetic tape rotatably retained therein has been known as a type ofmagnetic tape cartridge used as the recording medium of an externalstorage device of computers, etc. as described, for example, in JapaneseUnexamined Patent Publication Nos. 11(1999) -306722, 2001-148179, and2001-266533.

[0005]FIG. 4 is a perspective view of a magnetic tape cartridge 1 ofthis type, illustrating an overall structure of the cartridge with asliding door 11 opened. On a side wall of a cartridge case 4 composed ofan upper case 2 and a lower case 3 firmly fixed together as a unit, atape reeling-out opening 10 that extends to the upper and lower cases 2and 3 is formed in the vicinity of a corner section. The tapereeling-out opening 10 has a sliding door 11 which is slidable to openand close the opening 10. A magnetic tape 6 is used as a data storagemedium of computers and the like, and has a leader pin 5 firmly fixed atthe end, which is engaged by a pin holding member of a magnetic tapecartridge read/write apparatus for reeling out the magnetic tape 6 fromthe cartridge case 4, and loading onto the magnetic tape cartridgeread/write apparatus when the magnetic tape cartridge 1 is loadedtherein. The magnetic tape cartridge read/write apparatus is configuredand adapted to rewind the magnetic tape onto the reel 7 and bring backthe leader pin into the cartridge when the magnetic tape cartridge isunloaded.

[0006] The cartridge case 4 is composed of the upper case 2 and lowercase 3 made of a synthetic resin firmly fixed together as a unit, e.g.by screws as described, for example, in Japanese Unexamined PatentPublication No. 2001-148179, or by ultrasonic welding on the matingsurfaces of the side walls of the upper and lower cases 2 and 3 asdescribed, for example, in Japanese Unexamined Patent Publication No.2001-266533. The leader pin 5 is removably retained across the upper andlower cases with the axis line in up-down direction in the vicinity ofthe tape reeling-out opening 10 provided on the cartridge case 4, andthe sliding door 11 for opening and closing the tape reeling-out opening10 is urged by a spring toward a position to close the opening 10.

[0007] In the magnetic tape cartridge 1 structured as described above,the tape reeling-out opening 10 is formed in the vicinity of a corner ofthe generally square cartridge case 4, and a space for the pathway ofthe magnetic tape and the access path to the leader pin 5 by the pinholding member of the magnetic tape read/write apparatus needs to besecured around the place where the leader pin 5 is retained inside theopening 10, so that the screws for fixing the upper and lower cases cannot be used in that area, and consequently they are provided in placesaway from that area as described, for example, in Japanese UnexaminedPatent Publication No. 2001-148179. Therefore, the area of the cartridgecase 4 in the vicinity of the tape reeling-out opening 10 has a lowstrength, since the area has no fixed portion secured by screws, as wellas no side wall because of the opening 10, and moreover, a lead-inrecess 20 for the leader pin 5 is formed on the bottom surface of thelower case 3.

[0008] In handling the magnetic tape cartridge 1, the cartridge may besometimes dropped accidentally on the floor, and if it falls with thecorner having the tape reeling-out opening 10 facing downwards, crashingthe weak corner in bond strength against the floor, the case 4 is likelyto be damaged with the broken or cracked corner.

[0009] In this connection, it may be contemplated that the upper andlower cases are welded together as described, for example, in JapaneseUnexamined Patent Publication No. 2001 25-266533, in order to increasethe bond strength. But a portion of a weld deposit jointing the matingsurfaces of the upper and lower cases may stick out of the matingsurfaces, thereby cosmetic appearance is spoiled. In addition, theportion of the weld deposit sticking out of the mating surfaces may comeoff by frictions and contaminates the working environment. Further, aportion of the weld deposit may get into the case by the vibration ofthe ultrasonic horn during the welding process, and turns into so-calledwelding dust which causes degradation in the quality of the magnetictape cartridge.

SUMMARY OF THE INVENTION

[0010] In recognition of the circumstance described above, it is anobject of the present invention to provide a magnetic tape cartridgecapable of preventing a weld deposit from sticking out.

[0011] The magnetic tape cartridge according to the present inventioncomprises: a cartridge case composed of an upper and lower cases weldedtogether on the mating surfaces thereof by ultrasonic welding with aplurality of energy directors, and having a tape reeling-out opening ona side wall thereof; and a single reel of magnetic tape rotatablyretained therein, wherein each of said plurality of energy directorsprovided on one of said mating surfaces has an elongated shape, and isdisposed with the longitudinal direction thereof substantiallyperpendicular to the direction along the side wall of the upper andlower cases.

[0012] It is preferable, however, that the energy director provided onone of the mating surfaces near the end of the side wall of the upperand lower cases is extended, to the area in close proximity to the endof the side wall, in the direction parallel to the direction along theside wall.

[0013] Further, the magnetic tape cartridge according to the presentinvention comprises: a cartridge case composed of an upper and lowercases welded together on the mating surfaces thereof by ultrasonicwelding with a plurality of energy directors, and having a tapereeling-out opening on a side wall thereof; and a single reel ofmagnetic tape rotatably retained therein, wherein one of said matingsurfaces on which said plurality of energy directors are provided hasgrooves on both sides of said plurality of energy directors for trappingthe weld deposits made of said plurality of energy directors.

[0014] Preferably, the grooves on one of the mating surfaces fortrapping the weld deposits is created to enclose the plurality of energydirectors.

[0015] Still further, the magnetic tape cartridge according to thepresent invention comprises: a cartridge case composed of an upper andlower cases welded together on the mating surfaces thereof by ultrasonicwelding with a plurality of energy directors, and having a tapereeling-out opening on a side wall thereof; and a single reel ofmagnetic tape rotatably retained therein, wherein said plurality ofenergy directors provided on one of said mating surfaces are disposedoff-center on the inner side of the case with respect to the center ofsaid one of the mating surfaces in the direction of the thicknessthereof, and said one of the mating surfaces has a wall on the innerside of the case with respect to said plurality of energy directors forblocking the weld deposits made of said plurality of energy directorsfrom flowing out of said mating surfaces.

[0016] If the energy director has an elongated rib-like shape, the welddeposit formed thereby has a tendency to extend in the directionperpendicular to the longitudinal direction thereof.

[0017] In a magnetic tape cartridge according to the present invention,a plurality of elongated energy directors are disposed with thelongitudinal direction substantially perpendicular to the directionalong the side wall of the upper and lower cases, so that the welddeposits flow on the mating surface along the direction parallel to thedirection along the side wall of the upper and lower cases, thereby theweld deposits may be prevented from sticking out of the mating surfaces.In this case, the energy director near the end of the side wall of theupper and lower cases is extended to an area in close proximity to theend of the side wall in the direction parallel to the direction alongthe side wall, thereby the upper and lower cases may be welded togetherto the area in close proximity to the end of the side wall, while theweld deposits are prevented from sticking out of the mating surfaces atthe end of the side wall.

[0018] Further, in the magnetic tape cartridge according to the presentinvention, one of the mating surfaces on which the plurality of energydirectors are provided has grooves on both sides of the plurality ofenergy directors for trapping the weld deposits made of the plurality ofenergy directors, so that the weld deposits may be prevented fromsticking out of the mating surfaces, regardless of the direction inwhich the plurality of energy directors is extended.

[0019] Still further, in the magnetic tape cartridge according to thepresent invention, a plurality of energy directors provided on one ofthe mating surfaces are disposed off-center on the inner side of thecase with respect to the center of the mating surface in the directionof the thickness thereof, and the mating surface has a wall on the innerside of the case with respect to the plurality of energy directors forblocking the weld deposits made of the plurality of energy directorsfrom flowing out of the mating surfaces, so that the weld deposits maybe prevented from sticking out of the mating surfaces, even if theplurality of energy directors are extended in the direction along theside wall of the upper and lower cases. In addition, the intrusion ofthe welding dust may also be prevented by the wall described above.Further, providing the wall described above on the inner surface of theside wall of the upper and lower cases alternately across the matingsurfaces may greatly increase the strength of the mating surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is an enlarged perspective view of a magnetic tapecartridge according to the present invention, illustrating the structureof the relevant part of the lower case near the tape reeling-outopening.

[0021]FIG. 2 is an enlarged perspective view schematically illustratinga first embodiment of the present invention.

[0022]FIG. 3A is a plan view schematically illustrating a firstembodiment of the present invention.

[0023]FIG. 3B is a plan view schematically illustrating a modifiedarrangement of a first embodiment of the present invention.

[0024]FIG. 3C is a plan view schematically illustrating a secondembodiment of the present invention.

[0025]FIG. 3D is a plan view schematically illustrating a thirdembodiment of the present invention.

[0026]FIG. 4 is a perspective view of a conventional magnetic tapecartridge.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, the present invention will be described in detail byway of preferred embodiments illustrated in the accompanying drawings.

[0028]FIG. 1 is an enlarged perspective view of a magnetic tapecartridge according to the present invention that has substantially thesame structure as that of the magnetic tape cartridge 1 shown in FIG. 4,illustrating the structure of the relevant part of the lower case nearthe tape reeling-out opening. FIG. 1 shows a groove 12 for a slidingdoor 11 to slide along to open and close an opening 10, a mating surface13 on top of the side wall to be welded to an upper case by ultrasonicwelding, and a lead-in recess for a leader pin 5.

[0029]FIG. 2 is an enlarged perspective view of a first embodiment ofthe present invention, illustrating that a plurality of elongatedrib-like energy directors 15 are disposed on the mating surface 13 ontop of the side wall of a lower case 3 with the longitudinal directionsubstantially perpendicular to the direction along the side wall of themating surface 13.

[0030]FIG. 3A is a plan view of a first embodiment shown in FIG. 2,schematically illustrating that a plurality of energy directors 15 aredisposed on the mating surface 13 with weld deposits 16 to be formed byultrasonic welding.

[0031] If the energy director 15 has an elongated rib-like shape, theweld deposit 16 formed by the energy director 15 has a tendency toextend in the direction perpendicular to the longitudinal directionthereof, as illustrated in FIG. 3A. Therefore, placement of theplurality of elongated rib-like energy directors 15 on the matingsurface 13 in the direction substantially perpendicular to the directionalong the side wall of the mating surfaces 13 of the upper and lowercases 2 and 3, as in this embodiment, will cause the weld deposits 16 toflow on the mating surface 13 in the direction along the side wall, sothat the weld deposits 16 may be prevented from sticking out of themating surfaces 13.

[0032]FIG. 3B shows a similar arrangement to that shown in FIG. 3A,except that one of the energy directors 15 provided on the matingsurface 13 near the end of the side wall is extended to the area inclose proximity to the end of the side wall in the direction parallel tothe direction along the side wall. This arrangement of the energydirectors allows the upper and lower cases to be welded together to thearea in close proximity to the end of the side wall, while the welddeposit is prevented from sticking out of the mating surfaces at the endof the side wall.

[0033]FIG. 3C is a schematic plan view of the mating surface 13according to a second embodiment of the present invention, illustratingan arrangement in which the mating surface 13 has grooves 17 (indicatedby hatched lines) for trapping the weld deposits 16 made of the energydirectors 15. When the energy directors 15 are extended along thedirection parallel to the direction along the side wall, as shown inFIG. 3C, the grooves 17 may be provided only on both sides of the energydirectors in the direction parallel to the direction along the sidewall, but it is more preferable that the grooves 17 are created suchthat they enclose the energy directors 15.

[0034] The magnetic tape cartridge according to the second embodiment ofthe present invention may prevent the weld deposits from sticking out ofthe mating surfaces, regardless of the direction in which the energydirectors are extended.

[0035]FIG. 3D is a schematic plan view of the mating surface 13according to a third embodiment of the present invention, illustratingan arrangement in which the plurality of energy directors 15 aredisposed off-center of the mating surface 13 on the inner side of thecase with respect to the center of the mating surface in the directionof the thickness thereof, i.e., on a downward side of the center in FIG.3D, and a wall 18 is provided on the inner side of the case with respectto the plurality of energy directors for blocking the weld deposits 16formed thereby from flowing out of the mating surfaces.

[0036] The magnetic tape cartridge according to the third embodiment mayprevent the weld deposits 16 from sticking out of the mating surfaces13, even if the plurality of energy directors is disposed in thedirection along the side wall of the upper and lower cases, and thewelding dust generated during the welding process may be prevented fromentering into the case by the wall 18 described above.

What is claimed is:
 1. A magnetic tape cartridge comprising: a cartridgecase composed of an upper and lower cases welded together on the matingsurfaces thereof by ultrasonic welding with a plurality of energydirectors, and having a tape reeling-out opening on a side wall thereof;and a single reel of magnetic tape rotatably retained therein, whereineach of said plurality of energy directors provided on one of saidmating surfaces has an elongated shape, and is disposed with thelongitudinal direction thereof substantially perpendicular to thedirection along the side wall of the upper and lower cases.
 2. Amagnetic tape cartridge according to claim 1, wherein said tapereeling-out opening is formed across the upper and lower cases.
 3. Amagnetic tape cartridge according to claim 1, wherein one of saidplurality of energy directors provided on said one of the matingsurfaces near the end of the side wall of the upper and lower cases isextended, to the area in close proximity to the end of said side wall,in the direction parallel to the direction along said side wall.
 4. Amagnetic tape cartridge comprising: a cartridge case composed of anupper and lower cases welded together on the mating surfaces thereof byultrasonic welding with a plurality of energy directors, and having atape reeling-out opening on a side wall thereof; and a single reel ofmagnetic tape rotatably retained therein, wherein one of said matingsurfaces on which said plurality of energy directors are provided hasgrooves on both sides of said plurality of energy directors for trappingthe weld deposits made of said plurality of energy directors.
 5. Amagnetic tape cartridge according to claim 4, wherein said tapereeling-out opening is formed across the upper and lower cases.
 6. Amagnetic tape cartridge according to claim 4, wherein said grooves onsaid one of the mating surfaces for trapping the weld deposits arecreated to enclose said plurality of energy directors.
 7. A magnetictape cartridge comprising: a cartridge case composed of an upper andlower cases welded together on the mating surfaces thereof by ultrasonicwelding with a plurality of energy directors, and having a tapereeling-out opening on a side wall thereof; and a single reel ofmagnetic tape rotatably retained therein, wherein said plurality ofenergy directors provided on one of said mating surfaces are disposedoff-center on the inner side of the case with respect to the center ofsaid mating surface in the direction of the thickness thereof, and saidone of the mating surfaces has a wall on the inner side of the case withrespect to said plurality of energy directors for blocking the welddeposits made of said plurality of energy directors from flowing out ofsaid mating surfaces.
 8. A magnetic tape cartridge according to claim 7,wherein said tape reeling-out opening is formed across the upper andlower cases.